langgraph/docs/docs/cloud/reference/env_var.md

Environment Variables

The LangGraph Cloud Server supports specific environment variables for configuring a deployment.

LANGCHAIN_TRACING_SAMPLING_RATE

Sampling rate for traces sent to LangSmith. Valid values: Any float between 0 and 1.

See LangSmith documentation for more details.

LANGGRAPH_AUTH_TYPE

Type of authentication for the LangGraph Cloud Server deployment. Valid values: langsmith, noop.

For deployments to LangGraph Cloud, this environment variable is set automatically. For local development or deployments where authentication is handled externally (e.g. self-hosted), set this environment variable to noop.

LANGSMITH_RUNS_ENDPOINTS

For Bring Your Own Cloud (BYOC) deployments with self-hosted LangSmith only.

Set this environment variable to have a BYOC deployment send traces to a self-hosted LangSmith instance. The value of LANGSMITH_RUNS_ENDPOINTS is a JSON string: {"<SELF_HOSTED_LANGSMITH_HOSTNAME>":"<LANGSMITH_API_KEY>"}.

SELF_HOSTED_LANGSMITH_HOSTNAME is the hostname of the self-hosted LangSmith instance. It must be accessible to the BYOC deployment. LANGSMITH_API_KEY is a LangSmith API generated from the self-hosted LangSmith instance.

N_JOBS_PER_WORKER

Number of jobs per worker for the LangGraph Cloud task queue. Defaults to 10.

POSTGRES_URI_CUSTOM

For Bring Your Own Cloud (BYOC) deployments only.

Specify POSTGRES_URI_CUSTOM to use an externally managed Postgres instance. The value of POSTGRES_URI_CUSTOM must be a valid Postgres connection URI.

Postgres:

• Version 15.8 or higher.
• An initial database must be present and the connection URI must reference the database.

Control Plane Functionality:

• If POSTGRES_URI_CUSTOM is specified, the LangGraph Control Plane will not provision a database for the server.
• If POSTGRES_URI_CUSTOM is removed, the LangGraph Control Plane will not provision a database for the server and will not delete the externally managed Postgres instance.
• If POSTGRES_URI_CUSTOM is removed, deployment of the revision will not succeed. Once POSTGRES_URI_CUSTOM is specified, it must always be set for the lifecycle of the deployment.
• If the deployment is deleted, the LangGraph Control Plane will not delete the externally managed Postgres instance.
• The value of POSTGRES_URI_CUSTOM can be updated. For example, a password in the URI can be updated.

Database Connectivity:

• The externally managed Postgres instance must be accessible by the LangGraph Server service in the ECS cluster. The BYOC user is responsible for ensuring connectivity.
• For example, if an AWS RDS Postgres instance is provisioned, it can be provisioned in the same VPC (langgraph-cloud-vpc) as the ECS cluster with the langgraph-cloud-service-sg security group to ensure connectivity.